The present invention relates to the field of COMINT/ELINT (Communications Intelligence/Electronic Intelligence) signal processing, and more particularly to the detection of RF pulses.
Pulses which contain discontinuous waveforms having specific frequency characteristics, are often referred to as RF pulses even though such characteristics are not limited to the conventional radio frequency bandwidth. As is well known in the art, such RF pulses, can be detected with a conventional Chirp-Z analyzer. Such analyzers are designed to operate over a substantial bandwidth and function to present a forward (hereinafter dynamic) Chirp-Z transform containing the individual frequency components of a composite continuous wave (CW) signal, in a frequency segregated time domain. Each RF pulse is applied at one input of a mixer and output from an impulse driven expansion filter is applied at the other mixer input. A sweeping local oscillator (hereinafter SLO) is commonly utilized as the expansion filter and output from the mixer is directed to a compression filter from which the dynamic Chirp-Z transform is derived. In conventional Chirp-Z analyzers however, the dispersion of the expansion filter (SLO sweep time) is much greater than the duration of many RF pulses and the gain inherent to the dynamic Chirp-Z transform drops off in proportion with the difference existing therebetween. Other types of analyzers for detecting RF pulses are well known but ringing and distortion problems are inherent thereto, and little if any gain is possible therewith.